How about a new-fashioned coronavirus? Kills off the weak ones - can be used to justify whatever...?

That had crossed my mind, that perhaps one motivation was not to depopulate generally, but rather to rid society of those bothersome old people who are putting such a strain on economies that aren't producing enough young people to serve as a tax or labor base.

Yeadon also makes the mistake of saying 'I'm a scientist - therefore i'm right!' This is a large part of the problem - the culture of empiricism. Philosophers - the same dudes who invented all the freedoms we have, including democracy, also pointed out the flaws of empiricism as a philosophy. (a) we never have all the information - there's too much of it (b) it breeds a tendency to insist you're right (because you're an empiricist) and shut down other voices - which is anti-knowledge.

Good point, and this is why we need informed, open discussion. When did changing one's mind or being open to opposing ideas become a sign of weakness and cause for ridicule?